def print_models(unprinted_designs, completde_models):
    """
    模拟打印每个设计，直到没有未打印的设计为止
    打印每个设计后，都将其移到列表completed_models中
    :param unprinted_designs:
    :param completde_models:
    :return:
    """
    while unprinted_designs:
        current_design = unprinted_designs.pop()

        # 模拟根据设计制作3D打印模型的过程
        print("Printing model: " + current_design)
        completde_models.append(current_design)

def show_completed_models(completed_models):
    """显示打印好的所有模型"""
    print("\nThe following models have been printed:")
    for completed_model in completed_models:
        print(completed_model)

unprinted_designs = ['iphone_case', 'robot_pendant', 'dodecahedron']
completed_models = []

print_models(unprinted_designs, completed_models)
show_completed_models(completed_models)